Vacuum-indicator.



C. R. KEERAN.

VACUUM INDICATOR.

APPLICATION FILED SEPT.19,1911.

1 ,085, 1 34, Patented Jan 27, 1914.

h /fnesses: .fn renfor:

Cha es ia/fee an. I M 1 r CHARLES R. KEERAN, 0F BLOOMINGTON, ILLINOIS.

VAGUUMJNDICATOR.

Application filed September 19, 1911.

Specification of Letters Patent.

Patented Jan. 27, 1914.

Serial No. 650,270.

'0 all whom-it may concern:

Be it known that I, CHARLES R. KEERAN, a citizen of the United States. residing at- Bloomington, in the county of McLean and State of Illinois, have invented certain new and useful Improvements in Vacuum-Italicators, of which the following is a specification.

The present invention relates to a vacuum indicator which is in the form of a cap or closure adapted for use with a receptacle which is intended to be sealed by the vacuum process.

The salient object of the present invention is to provide a cap or closure which will be susceptible to a flexing movement. in accordance with the condition of the air within the receptacle, and to construct said cap so that its movements will be entirely automatic and in conformity to the changes of air conditions within the receptacle, thereby producing an efficient and automatic vacuum indicator.

Another object of the invention is to utilize this flexing property of the cap or cover so as to provide an indicator which will give to the user both an audible and a visual indication of the state of the seal. And a further objectof the invention is to provide an indicator which is cheap and simple of construction, and which is adapted for use with any form of receptacle.

The invention further consists in the features of construction and combination of parts hereinafter described and claimed.

In the drawings, Figure l is a view showing the indicator in the position which it assumes when a state of vacuum is not present within the receptacle, and therefore no seal produced; Fig. 2 is a View showing the position assumed by the indicator when a vacuum is created and the seal produced; and Fig. 3 is a plan view of the cap or cover.

In the art to which the present invention relates, the sealing of the receptacle is produced by a less atmospheric pressure within the receptacle than upon the outside of the receptacle and then depending upon this differential pressure of the outside air to maintain the cover in position and effect a sealing of the receptacle. This creating of a differential air pressure upon the inside and outside of the jar is brought about either by a heating of the air inside of the jar or by placi g the jar in a acuum ma hin nd then exhausting a part of the air therefrom.

{The former method is the one commonly utilized by the housewife, and one strong feature of the present invention is that it is i just as operative with this method of form- 1 ing the seal as it is when the seal is produced by inserting the receptacle within a i vacuum machine. In the formation of seals of this nature. it is quite a dii'licnlt matter lor the ordinary user to determine whether or not the seal is perfectly made. and it frequently results that a can of goods is set away and the non-efliciency of the seal not discovered until some time after the can ning, with the result that the produce is spoiled.

As stated. it is the salient object of the present invention to provide a simple and accurate means for indicating when this seal is effectively made, and to provide an audible indication. as well as a visual indication, which will inform the user as to the air con ditionswithin the jar. and hence-as to the efliciency of the seal.

The indicator as illustrated in the drawings consists of a cap-like member having a top portion and a depending side portion 6, the side portion being adapted to engage the outer upper surface of the jar. The form of jar illustrated in the drawings is not to be considered as a limitation upon the present. invention. since it is used entirely for illustrative purposes. It is understood that the indicator may he applied to any suitable form of receptacle.

The top portion of the indicator in the form shown is configured to receive a ring of sealing substance 7. which rests against the top surface of the jar. The body of the indicator is made of spring metal, so that the top surface is susceptible of a flexing action, and said surface. as shown in the drawings, is curved or configured to permit of such a flexing movement. The curve is of a nature so that a spring property is present in the surface. which normally tends to hold it in the position shown in Fig. 1. This is an important point of the present invention, since it is primarily because of this feature that the top is enabled to return to normal position automatically if the seal is defective. Experiments have shown that not every form of curvature is susceptible to this action, and hence acurvature of the form to generate this spring property is an essential and salient feature of the present invention. By forming the p in his mann r, h ever a flexing thereof occurs, a sharp click or audible signal will be given, indicating either the forming or breaking of the seal, as the case may be. When the seal is not made, the user can determine the same by passing his finger over the top surface of the indicator and feeling for the ridge or lump which is there present when the seal has not been made; or by looking at the top surface, this rise in the surface of the cover can also be discovered and the state of the seal determined in this manner. Then the seal is made, a visual determination thereof is created by the downward curving of the body of the top portion of the indicator. It is thus evident that the three methods of de termining whether or not a perfect seal has been produced are present: First, the audible indication; second. the visual indication; and third, the indication by thetouch. In utilizing this last method of indication, the user, in addition to the feeling for the bulge in the indicator, can obtain an indication by a pressure upon the top surface thereof. if the seal is not made, the top surface will flex with the pressure of the hand; and if it is made, no flexing will be possible, because of its being drawn down to its fullest extent.

ll am aware that it is not radically new to 1)1'()"l(l8 a flexible top for a jar cover, but so far as l am aware no one has ever conceived the idea of forming a cover so that it will be susceptible to a flexing action which will act automatically and serve as an indicator to convey to the user the condition of the seal, thus utilizing the coveras a vacuum indicator. In the flexible cap or cover commonly employed in the art, there will be a flexing downward of the top surface of the cover when the seal is made, but the automatic restoration of the top surface of the cap to normal position when the seal is broken or not perfect is not present. If the seal breaks, the cover still remains in its dowmvardly depressed position, so that there is no indication given of the broken seal. Thus, so far as any value as an indicator is concerned, this type of coverwould be totally worthless. y

In using the present invention, a vacuum is created in the receptacle, either by a heating of the air in the interior of the receptacle, or by drawing out a portion of said air, the cap or cover is then placed on the receptacle. If the vacuum is properly made, the effect of the air pressure upon the outside will flex the top portion of the cover inwardly, as shown in Fig. 2, and such flexing will be accompanied by a sharp click as the surface moves from the position shown in Fig. 1 to that shown in Fig. 2, this clicking giving to f-the user an audible indication that the seal has been formed.

After the goods have remained in the remine whether or not a perfect seal has been made. This can be readily done either by looking at the top surface of the cap or by a pressure of the finger upon said surface, the indication of a bad seal being given by the ability of the user to press said surface inward-1y and the click produced by such a pressing operation. As the jars are being filled, if an indication is given that a seal is mad e, and the can set to one side, and a short while afterward the seal becomes broken, such breaking will be accompanied by a sharp click as the cover moves from the position shown in Fig. 2 to that shown in Fig. 1. Upon hearing such click, the user would be notified of the breaking of the seal upon one of the receptacles, and would set about to determine which of them had the imperfect seal. By means of these indications, it is a simple matter to determine the presenceof an imperfect seal, and thus the liability of the goods becoming spoiled, because of the ignorance of such a condition, is obviated.

The present invention is equally applicable to the ordinary tin can, and the indicator may be formed on the top or bottom of said can, as desired. The cans, upon being filled and after a proper period of time, can be readily tested as to the efficiency of the seal by an inspection of the indicator, or the bad formation of the seal .can be detected by the audible indication heretofore described. it do not, therefore, limit myself to a use of the indicator with glass jars or similar receptacles, but desire it to be understood that it can be used in any field where a metal closure is employed and where it is desirable to provide an indication of the efiiciency of the seal.

I claim:

A' vacuum indicator for hermetically sealed receptacles consisting .of a disk of spring metal having a portion of domeshaped formation arranged to permit flexing movement thereof in two directions beyond the plane of the remaining surface of the disk, said flexing producing a distinct sound, said portion being flexible to its extreme position in each direction in accordance with as described.

CHARLES R. KEERAN.

. Witnesses: g

, WM. PIBono,

FRANCES M. Fnos'r.

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